William d



(No Model.) 2 Sheets-Sheet 1. W. D. GRAY.

ROLLER GRINDING MILL. No. 388,967. Patented Sept. 4, 1888.

WITNESSES. l/V VEA/TOH (No Model.) 2 Shets-Sheet 2..

W, D. GRAY.

ROLLER GRINDING MILL.

No. 388,967. Patented Sept-4,1888,

n'rmvir @rrrcn.

WILLIAM D. GRAY, OF MILWAUKEE, WVISGONSIN, ASSIGNOR TO E. P. ALLIS & (30., OF SAME PLACE.

ROLLER GRlNDlNG-MlLL.

SPECIFICATION f Iming part of Letters Patent No. 388,967, dated September 4, 1888.

Application filed June 23, 1884. Serial No. 135,793.

To aZZ whom it may concern.-

Be it known-that I, WILLIAM D. GRAY, of Milwaukee, in the county of Milwaukee and State of Vvisconsin, have invented a certain new and useful Improvement in Grinding Mills, of which the following is a full, clear, and exact specification.

At the present day roller grinding-mills are commonly constructed with two cooperating grinding-rolls, one of which is movable to and from its companion in order that the grinding action may be stopped and started without stopping the rotation of the rolls. Mechanisms of various forms are used in connection with the movable roll to effect its instantaneous adjustment, these mechanisms of the various types being commonly known in the art as roll-spreading mechanisms and occasionally as roll-adjusting mechanisms. Roller-mills are commonly provided with a feed-roll and with a driving-clutch, by means of which the roll may be stopped and started at will.

Heretofore the roll-spreading mechanism and the feed-roll driving-clutch have been variously connected by intermediate devices in such manner that the spreading action of the rolls was accompanied by the stoppage of the feed-roll and the closing of the grinding-rolls accompanied by the starting of the feed-roll. In a mill thus organized the unground material lying upon or between the grinding-rolls is delivered between them in an unground condition as they are separated. The aim of my invention is principally to avoid the passage of the unground material between the rolls, and to this end I connect the rollspreading mechanism and the feed-driving clutch to a common operating device in such manner or in such relation that the movement of the parts in one direction effects the disconnection of the feed-driving clutch and the stoppage of the feed prior to the spreading of the grinding-rolls, and that their movement in the opposite direction effects the engagement of the clutch and starting of the feed previous to the closing of the grinding-rolls. Under this arrangement the grinding-rolls are, on

. the one hand, permitted to operate after the feed-roll has stopped its rotation for a sufficient length of time to reduce the material (No model.)

already delivered to them, and, on the other hand, are caused to close or resume the grinding position after the starting of the feed-roll.

As regards the construction and arrangement of the feed-rolls and their spreading mechanism, they may be of any ordinary character now known in the art. The feed-roll, its driving-clutch, and the clutch-operating devices may also be of any ordinary construction, the essence of the invention residing in the connection of these known mechanisms in such manner-that is to say, in such relation that they are caused to operate successively in the order named instead of simultaneously.

In the accompanying drawings 1 have represented my improvement embodied in its preferred form in a double-roller mill and also in a single-roller mill.

Figure 1 represents a side elevation of the upper portion of a double-roller mill (that is to say, a mill with two pairs of grinding-rolls and two feed-rolls) provided with my improvement. Fig. 2 is a top plan view showing the feed-connections between the feed-driving clutch and the roll-spreading mechanism. Fig. 3 is a plan View, partially in section, showing the clutch in modified form. Fig. 4

is a side elevation of a single mill having the invention incorporated therein.

Referring to Figs. 1, 2, and 3, A represents the frame or body of the mill; B B, two horizontal grinding-rolls, sustained by fixed bearings on the frame; G O, the movable grindingrolls, supported by upright arms D, which are pivoted at their lower ends to the frame. The two arms D of each roll are connected by rods E to eccentrics F on a cross-shaft, G, the rotation of which moves the roll to or from its companion into or out of its grinding position. There are two of the rockshafts G, one for each movable roll. Their ends are provided with crank-arms a, and these arms are connected by a horizontal bar, H, the movement of which adjusts the two rolls 0 simultaneously.

The foregoing parts, commonly known as the roll-spreading mechanism, are essentially the same as in various patents heretofore granted to me, and are not claimed herein.

At the top of the machine are two feed hoppers, or a hopper with two throats, to de- ICO liver material to the respective pairs of rolls. Below the respective throats, above the grinding-rolls, are two horizontal feed-rolls, J J, of ordinary form and arrangement. The roll J has its shaft provided with a fixed pulley, K, which receives motion through a crossed belt, L, from a pulley, M, on the roll J. The roll J is also provided with a loose driving-pulley, N, connected by a belt, 0, with a pulley, P, on the journal of one of the grinding-rolls, or on any other revolving member of the machine.

The pulley N is secured by collars on the rock-shaft or like devices from moving laterally thereon, and has its hub toothed on one side to engage a sliding clutch, Q, splined upon the shaft for the purpose of imparting motion to the feed-rolls. The clutch is grooved circu-mferentially to receive the forked end of an angular shipping-lever, R, pivoted to the main frame and extended to the opposite side of the machine, where its end is arranged in position to engage and receive motion from the roll-spreading bar II. It will be observed that this bar H is provided on the under side near its opposite ends with two notches or shoulders, a a, which engage alternately with the feed-controlling lever as the latter approaches the end of its movement in one direction or the other, this construction allowing the rollspreading bar a certain amount of movement independently of the clutch-controlling lover, or, in the language of a mechanic, allowing a certain amount of lost motionbetween the two parts.

When the parts stand in the position of Figs. 1 and 2, with the roll-spreading bar H at the left, the grinding-rolls stand apart and the feed-rolls are at rest. If the bar H be now moved to the right, it will first move the lever B and engage the feed-driving clutch,and then,

disengaging from lever R,wi1l by its continued movement effect the closing of the grindingrolls and re-engage the lever It. It will be perceived that in this manner the rolls are brought to a grinding position after the feedrolls are started. If the bar be returned to Ward the left, its shoulder will first actuate the clutch'lever and disengage the clutch, so as to stop the feed, after which the bar, continuing its movement, will momentarily disengage from the lever, then effect the spreading of the rolls, and finally re-engage the lever. During the time between the stoppage of the feed-roll and the spreading of the grinding-rolls the latter will reduce the material resting between them. The lever B may be moved by hand and adjusted into or out of either of the notches a a, in order to stop and start the feed at will, independently of the adjustment of the grinding-rolls. In place of the toothed clutch a conical friction-clutch of ordinary form, as shown in Fig. 3, may be employed to drive the feed-roll.

Referring to Fig. 4, the mill therein represented is identical with that shown in Figs. 1 and 2, except that one pair of grinding-rolls and one of the feed-rolls, together with the devices for driving them, are omitted.

In Fig. 4,Arepresents the frame; B,thestationary grinding-roll; O, the movable roll, and D the pivoted support for one end of the movableroll; E, its controlling rod; F,the eccentric; G, the cross-shaft carrying the eccentric, and H the spreading-bar connected to the crankarm a on the end of the shaft G and also supported by a special swinging arm, a, on a shaft, 0, this second shaft and its arm being provided simply to uphold the bar. J represents the feeddriving clutch and R its operating-lever. In form, arrangement, and mode of action the separts are identical with those shown in Figs. 1 and 2.

While I have described the preferred construction, it will be understood by the skilled mechanic that the details of construction may be modified without departing from thelimits of my invention, provided the connecting device between the roll-spreading mechanism and the feed-driving clutch operate, substantially as herein described, to effect the disengagement of the feed-driving clutch before the spreading of the rolls and the closing of the rolls after the'engagement of the clutch.

I believe myself to be the first to construct a mill in which the parts areconnected to secure this result.

Having thusdescribed my invention, what I claim is- 1. In a roller grindingmill, a hopper, two grinding-rolls, one of which is movable, and a spreading mechanism for throwing the movable roll into and out of its grinding position, in combination with a movable bar, H, for operating said roll-spreading mechanism, provided with shoulders at a, the feed-roll, its driving-clutch, and the clutch-operating lever arranged to engage the shoulders at and a, as described.

2. In a grinding-mill, the combination of no the hopper, the feedroll, the feed-roll drivingclutch Q, and the clutch-operating lever B,1in combination with the two grinding-rolls, one of which is movable, the support for the movable roll, the rock-shaft G, the intermediate connections between said roclcshaft and the movable roll-support, the swinging arms a, and the movable bar H,connected to said arms, and adapted, as described, to engage with and disengage from the lever B, as described.

3. In a roller grinding-mill, the combination, with the grinding-rolls and their spreading mechanism, as usual, of the feed-roll and its driving-clutch, as usual, and a clutch-operating device connected to the roll-spreading mechanism, as described, in such relation that the disconnection of the clutch and the spreading of the rolls are caused to occur, in the order named.

4. In a roller grinding-mill, two grindingrolls and a spreading mechanism, as usual, a feed-roll and its drivingclutch, and a clutchoperating lever adapted to interlock in two reverse positions with the spreading mechanism, and movable at will from one to the other connection from the clutch to the spreading by hand, whereby thestopping and starting of mechanism in position to compel the engage to the feed may be effected automatieailyin conment of the clutch and closing of the rolls, in nection with the spreading of the rolls or inthe order named.

5 dependently by hand. WILLIAM D. GRAY.

5. In a roller grinding-mill, the combination Witnesses: of the grinding-r011 and a spreading meehan- I RICHARD HOPPIN,

ism, the feed-r011 and its driving-clutch, and a E RICHARD BIRKHOLZ. 

